The present invention relates to an electronic locking device which consists of a lock and key cards, the lock electronics of which has a data storage and which can be coupled with a mobile printer which can be connected to the lock electronics and retrieve data, the locking device having an insert shaft for the key cards in which a card reader is arranged and which is provided at its end with a socket connected to the lock electronics, for a card-shaped coupling element of the printer which can be inserted into the insert shaft and has electrical contacts.
Such a locking device is known from European Patent 132 627. By utilizing the insert shaft both for inserting the key cards and for the coupling element, a particularly clear and simple construction has been created since a separate insert opening for the connection to the mobile printer is unnecessary. Furthermore, as a result hereof, a concealed arrangement of the socket is made possible, which offers a certain protection against unauthorized manipulation. Nevertheless, in the known arrangement it cannot be excluded that unauthorized access to the data storage of the lock takes place in the manner that an unauthorized person inserts a coupling element into the insert shaft of the lock and in this way establishes an electrical connection with the receptacle. Status data can thus be interrogated or printed out by the mobile printer, indicating with what key cards and at what time a locking of the lock took place, whether the key card was merely inserted or whether the lock mechanism was also actuated, and whether there were any malfunctions of the lock. The retrievable information is customarily up-to-date, i.e. an up-to-date data base is maintained which continuously writes over older data. It is readily understood that the retrievable data should be accessible only to authorized persons.
The connection of the printer constitutes a special operating mode of the lock; in normal operation (access control operation) a query for the coding and a comparison with the lock code take place upon insertion of a valid key card into the insert shaft. If the key-card information enquired for corresponds to the values stored in the memory, then a locking pulse is produced which makes the transfer of the lock into release position possible. Such locking devices can thus be used wherever access to certain areas is to be permitted only for authorized persons.